Trike Frame RedesignConcept Design

Fiona HughesGina PolicelliJodie Wu

Community Partners Response Biggest problem with current tricycle frames:

– (i)The Frame is not adjustable though it is made of standard size to suit most users and small size is also available.

– (ii)It is very bulky Reasons for current tricycle breakage:

– “Our design is made of round tubing having several bends forming a base frame. If the tube is flattened on bending or the material is a bit thin then it breaks easily. Also if the type of tubing frame do not withhold the weight of the persons then it breaks.”

Most time consuming part of building a frame: Bending the frame

Most expensive frame material: Round hollow tubing 25 X1.5 mm for base frame.

Man-hours to produce a frame: 5 hours

Community Partners Concerns Does the size and weight of tricycle cause problems for

the users?– Yes it is bulky and weighs almost 25kg.

Are there any size limitations? – Yes. The oversize people will have to use the stronger material

and also the tricycle has to be wider and extra large for accommodation.

Where are the tricycles sold? – Large number of tricycles are given free to the disabled

persons wither from the workshops or the specified project where they are delivered for handing over.

How are they transported from the shop to the users home? – They are transported by vehicles e.g. courier services it far or

the owners come for handing over and cycle them to their homes.

Functional Requirements Strength: withstand 350 lbs of load

– Strengthen and stiffen high moment areas Manufacturing time: <=5 hours Frame Materials: Cost<$200-TBD Size: <= 50” in length and 26” in width

(including wheels) Seat: More comfortable, adjustable,

waterproof Shippable: Stackable Design

Defining the Concept

Concept:– Adjustable to the user– Stackable Frame for shipping

Goals: – To address this concept by

developing modules– Develop Most Critical Module

Our Concept and Modules

Most Critical Module:Sturdy Base Frame

Features/Advantages:– Rectangular pieces

(stronger base)– Distribution of load

Risks: 1) Joint issues between

square and circular cross sections

2) Attaching the stem in terms of sturdiness

Countermeasures:1) Place circular pipe

against the square pipe rather than square pipe against the circular pipe

2) Use a pipe fitting in the section

Stackable Frame

Features/ Advantages:

– Shippable to more clients

– Lowers shipping cost

Countermeasures:1) Provide a manual (with drawings)2) Increase the safety

factor

Risks1)Assemblers on receiving

side may not be able to put trike together

2)Possible weakening of structure

The Adjustable Seat (with

hand tools)

Features/Advantages:– Adjustable to user– Biomechanically

optimized Risks:

1) Adjustability over time Countermeasures:

1)Maintenance Guide

The Sliding Tray/Storage

Features/Advantages:– Convenience– Small Business

Possibilities Risk:

1) May tip tricycle over Countermeasures:

1) Provide Counterweights, lower center of gravity

Plan and Countermeasures Plan:

– Develop most critical module first– Solid model everything– Gather all materials and arrange lab times

by end of April– Build Prototype

Countermeasure: – Build upon solid model to make a manual so

design can be constructed in machine shop in Africa